2 Answers
2

The question is short but the answer could be very long. If you are not using ASP.NET MVC then we have to regard your ASPX codebehind as page controllers, and the workflow is implicit in how the controllers redirect the user from page to page.

If you want WF foundation to govern page navigation, then you are looking at re-architecting so that WFs handle events.

I would install Windows Server AppFabric on the web server and host your WF there. Make sure that the first message is linked to the user's session, with CanCreateInstance=true. Consume the WF as a service using net.pipe for example. You would then need to significantly re-work the ASP.NET web site to delegate its navigation logic to the WF service, as though it was a front controller, and maybe use ASP.NET MVC to wrap the WF into controllers.